Project Summary/Abstract Over one-third of children in the U.S. are overweight or obese and at risk for short-term and long-term health consequences, including diabetes, hypertension, heart disease and certain types of cancer. Substantial evidence exists on reducing sugar-sweetened beverage (SSB) consumption as a critical dietary target for childhood obesity prevention. Efficacious behavioral interventions targeting SSBs are lacking, particularly among low-income and ethnic minority early and pre-adolescent youth who have higher SSB intake and obesity risk. Youth empowerment interventions hold potential for catalyzing behavior change in childhood obesity intervention contexts and may be particularly engaging for low-income and ethnic minority youth. However, few studies of youth empowerment health interventions have utilized rigorous study designs or examined empowerment as a mediator/mechanism of change. To this gap, we worked collaboratively with Boys and Girls Clubs of America (BGCs), a national system of afterschool care that reaches 4 million youth annually, to develop and pilot-test a community-based youth empowerment intervention on reducing SSB intake and preventing childhood obesity. Grounded in Empowerment Theory, the intervention targets SSB consumption through health sessions that empower youth through developing their confidence and skills; narrative sessions that empower youth through cultivating critical thinking, and youth-led activities that empower youth through opportunities to produce change within their families. The resulting H2GO! intervention is designed to be delivered within BGCs by BGC staff. Building on our successful pilot study of H2GO!, we are now positioned to test the efficacy of the H2GO! intervention in collaboration with the BGC network in MA, which collectively serves over 160,000 children each year. Using a cluster-randomized design, a total of 10 BGC sites will be randomly assigned to the H2GO! intervention or a wait-list, usual care condition. A total of 450 parent-child pairs (N=45 parent-child pairs per site) will be enrolled. Data will be collected at baseline, 2 months, 6 months, and 12 months and include child anthropometrics, SSB and water intake, and youth empowerment. Specific aims of the proposal include: 1) test the efficacy of the H2GO! intervention on child BMI z scores using a cluster randomized controlled trial; 2) test the efficacy of the H2GO! intervention on child SSB and water intake; 3) examine youth empowerment as a mediator of intervention effects. Findings from this proposal will provide evidence of youth empowerment as an approach to reduce SSB intake and obesity risk and contribute to a long-term goal of producing an intervention model for childhood obesity prevention that is well-positioned for dissemination through youth-based settings.